build.sh failure for aarch64

[Mayuresh <mayuresh%acm.org@localhost>]

I am completely new to use of build.sh. Trying to build aarch64 on amd64
9.2 using a recent source snapshot.

My command was:

    ./build.sh -U -u  -j4 -m evbarm -a aarch64 release

It fails with:

    nbmtree: failed at line 4151 of the specification
    *** Failed target: /usr/src/obj/destdir.evbarm/METALOG.sanitised
    *** Failed commands:
            <${METALOG}  ${${MKUPDATE} != "no" :? ${METALOG_REMOVE_DUPLICATES} | :}  sort | ${TOOL_MTREE} -CSM -k all -R time -N ${NETBSDSRCDIR}/etc  >${METALOG}.new
            => </usr/src/obj/destdir.evbarm/METALOG   /usr/src/obj/tooldir.NetBSD-9.2-amd64/bin/nbawk '{ a[$1] = $0; } END { for (f in a) print a[f]; }' |   sort | /usr/src/obj/tooldir.NetBSD-9.2-amd64/bin/nbmtree -CSM -k all -R time -N /usr/src/etc  >/usr/src/obj/destdir.evbarm/METALOG.new
            mv ${METALOG}.new ${METALOG}.sanitised
            => mv /usr/src/obj/destdir.evbarm/METALOG.new /usr/src/obj/destdir.evbarm/METALOG.sanitised
    *** [/usr/src/obj/destdir.evbarm/METALOG.sanitised] Error code 1
    
    nbmake[4]: stopped in /usr/src/distrib/sets
    1 error

Please advise.

-- 
Mayuresh